The present disclosure relates generally to simulating downhole formation characteristics and, more particularly, the present disclosure relates to methods and apparatuses for testing lost circulation materials for subterranean formations.
Subterranean drilling operations typically utilize drilling fluids to provide hydrostatic pressure to prevent formation fluids from entering into the well bore, to keep the drill bit cool and clean during drilling, to carry out drill cuttings, and to suspend the drill cuttings while drilling is paused and when the drilling assembly is brought in and out of the borehole. When drilling into certain formation types, some of the drilling fluid may seep into and become trapped in the formation. This is particularly problematic in vugular formations, which include numerous cavities, known as vugs. If enough drilling fluid is lost to the formation, additional drilling fluid must be introduced into the borehole to maintain drilling efficiency. This can become expensive if large amounts of the drilling fluid are lost.
To prevent drilling fluid loss into vugular formations, lost circulation materials (LCMs) may be added to the drilling fluid. The LCMs typically are typically fibrous (e.g., cedar bark, shredded cane stalks, mineral fiber and hair), flaky (e.g., mica flakes and pieces of plastic or cellophane sheeting) or granular (e.g., ground and sized limestone or marble, wood, nut hulls, Formica, corncobs and cotton hulls) materials. In certain other instances, LCMs may include reactive chemicals which set and harden within the vugs. The LCMs are intended to plug the vugs, preventing the vugs from capturing the fluid portions of the drilling fluid. Unfortunately, testing the effectiveness of LCMs for a particular formation is problematic. For example, current test methods are generally not repeatable, making it difficult to compare the relative effectiveness of two LCMs on the same formation. Additionally, current testing methods cannot accurately model the wide range of vug sizes, particularly the large vugs, needed to simulate vugular formations. As such, what is needed is an apparatus for scalable, repeatable testing of LCMs in vugular formations.
While embodiments of this disclosure have been depicted and described and are defined by reference to exemplary embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are examples only, and not exhaustive of the scope of the disclosure.